What's new in Swift 6.4? | Diagnose Attribute

[00:00:00]What is new in Swift 6.4? Part 2.

[00:00:03]>> Swift 6.4 introduced a new attribute called diagnose, giving developers fine-grained control over compiler diagnostics. Let's look an example.

[00:00:14]Here, we have some code running in a project configured to treat all deprecated warnings as errors. While that's generally a good practice, there are some situations where we might want a little more flexibility. Before diagnose, this was impossible. It was all or nothing. But, take a look at what happens when we add this attribute. In this case, I'm using the deprecated declaration diagnostic ID, which detects the use of deprecated APIs. The second parameter can be configured as ignored, which suppressed the diagnostic entirely, warning, which emits a warning, or error, which blocks compilation until the issue is resolved.

[00:00:56]Here's another example, this time using the no usage diagnostic ID, which detects variables that are declared but never used. Those are just two examples, but Apple actually added many more diagnostic IDs for different situations.

[00:01:12]The problem is that at the time I'm recording this video, there's almost no documentation about them. So, I dug through the Swift source code myself and put together a post explaining every diagnostic group currently available.

[00:01:26]Link in the description.

[00:01:28]>> And if you want to learn more Swift, subscribe.